Blood sampling without blood draws for in vivo pharmacokinetic studies in rats

• Published in: Journal of pharmaceutical and biomedical analysis Vol. 47; no. 4; pp. 907 - 912
• Main Authors: Musteata, Florin Marcel, de Lannoy, Inés, Gien, Brad, Pawliszyn, Janusz
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.08.2008; Elsevier Science
• Subjects: Acetonitriles - chemistry; Analysis; Analytical, structural and metabolic biochemistry; Animals; Anti-Anxiety Agents - blood; Anti-Anxiety Agents - pharmacokinetics; Area Under Curve; Biological and medical sciences; Buffers; Calibration; Diazepam - blood; Diazepam - pharmacokinetics; Free concentrations; Fundamental and applied biological sciences. Psychology; General pharmacology; Half-Life; Hydrogen-Ion Concentration; In vivo sampling; LC/MS/MS; Lorazepam - chemistry; Male; Medical sciences; Metabolic Clearance Rate; Pharmacokinetics; Pharmacology. Drug treatments; Phosphates - chemistry; Rats; Rats, Sprague-Dawley; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Sodium Chloride - chemistry; Solid phase microextraction; Solid Phase Microextraction - methods; Solutions - chemistry; Technology, Pharmaceutical; Solid phase microextraction; Free concentrations; In vivo sampling; Pharmacokinetics; LC/MS/MS; In vivo; Biological fluid; Vertebrata; Mammalia; In vivo sampling;Solid phase microextraction;Pharmacokinetics;LC/MS/MS;Free concentrations; Rat; Animal; Rodentia; Sampling; Mass spectrometry; Blood
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2008.03.028

Pharmacokinetic (PK) studies in rats typically involve removal of serial blood samples following dosing. This research illustrates the development of a fast in vivo microextraction technique that has the potential to partly replace current sampling techniques based on blood draws, especially in the case of small animals. The proposed sampling procedure is based on solid phase microextraction (SPME), an approach that has continued to revolutionize sampling and sample preparation ever since its discovery a decade ago. In vivo microextraction is faster than conventional methods, interferes minimally with the investigated system, minimizes errors associated with sample preparation and limits exposure of lab personnel to hazardous biological samples. Here we show the successful application of fast microextraction during a full PK study with diazepam in rats. The results were found to correlate very well with a standard analytical method. Three calibration strategies – external, standard on the fiber, and double extraction – were employed to correlate the amount extracted with the in vivo concentration. Our results demonstrate the unique advantages of this technique and highlight its utility as a valuable new tool for fast bioanalysis in support of in vivo sampling and PK studies, particularly during the early drug discovery process. This approach can be used not only for drugs, but also for other exogenous or endogenous compounds.